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Environmental Impact Statement
Arrow LNG Plant
Coffey Environments 7033_7_Ch22_v3
22-1
22. NOISE AND VIBRATION
This chapter describes the existing noise and vibration environmental values of the study area,
assesses the impacts of project construction and operation on these values and describes the
avoidance, mitigation and management measures Arrow Energy will implement through project
design to protect these values.
This chapter is based on the findings of the noise and vibration impact assessment conducted by
Sonus Pty Ltd (Sonus) (Appendix 16, Noise and Vibration Impact Assessment).
Objectives have been developed based on relevant legislation with the aim of protecting the
existing environment and environmental values. Project objectives for noise and vibration are
provided in Box 22.1
Box 22.1 Objectives: Noise and vibration
• To minimise the potential for noise and vibration to adversely affect sensitive receptors during project
construction and operation.
• To achieve relevant environmental noise and vibration criteria during construction and operation.
• To minimise noise and vibration impacts on terrestrial animals (including bats) and birds (avifauna)
(particularly migratory species).
Noise impacts on terrestrial animals and avifauna are addressed in Chapter 17, Terrestrial
Ecology. Impacts on the marine environment relating to underwater noise generated by the
project are addressed in Chapter 19, Marine and Estuarine Ecology.
22.1 Legislative Context and Standards
This section outlines the specific legislation, policies and guidelines that are designed to protect
the values of the environment within and surrounding the study area. These provide the
framework within which the project specific noise and vibration criteria have been developed.
22.1.1 International Guidelines
The World Health Organisation (WHO) developed guidelines for community noise to protect
people from annoyance during daytime (7.00 a.m. to 6.00 p.m.) and night-time hours (6.00 p.m. to
7.00 a.m.). The guidelines state that, to protect people from serious noise related annoyance
during the daytime, the outdoor sound pressure level should not exceed 55 dB(A) for a steady
continuous noise. To avoid sleep disturbance as a result of construction noises, the guidelines
require that the noise level outside a bedroom window should not exceed 45 dB(A) (Berglund et
al., 1999).
22.1.2 State Legislation, Guidelines and Standards
The legislation and guidelines that are relevant for the establishment of appropriate noise
assessment conditions are outlined below:
• Environmental Protection (Noise) Policy 2008 (EPP (Noise)). This policy defines the
environmental noise values for sensitive receptors. The environmental values to be enhanced
or protected under this policy are:
– The qualities of the acoustic environment that are conducive to protecting the health and
biodiversity of ecosystems.
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– The qualities of the acoustic environment that are conducive to human health and
wellbeing, including ensuring a suitable acoustic environment for individuals to sleep, study,
learn or be involved in recreation (including relaxation and conversation).
– The qualities of the acoustic environment that are conducive to protecting the amenity of
the community.
The EPP (Noise) will be used as the main method of assessing noise from the project at
sensitive receptors during the day, evening and night-time periods. The daytime period defined
by the policy is between 7.00 a.m. and 6.00 p.m., the evening is between 6.00 p.m. and
10.00 p.m., and the night-time period is from 10.00 p.m. until 7.00 a.m.
The EPP (Noise) does not include any provisions for construction noise limits during daytime
hours. However, all reasonable and practical measures are to be taken to reduce the noise
impact on sensitive receptors.
• Draft guidelines for the assessment of low-frequency noise (DERM, 2002b). This guideline
provides criteria for the assessment of low-frequency, project-generated noise. For non-tonal,
low-frequency noise between 20 and 200 Hz, the draft guideline states that the noise is
acceptable if the contribution of low-frequency noise indoors at a sensitive receptor does not
exceed 20 dB(A) during the evening or night, and 25 dB(A) during the day.
• Noise measurement manual (EPA, 2000). This manual sets out the noise measurement
procedures and methodology. Noise measurements performed during the impact assessment
were made in accordance with this manual.
• Planning for noise control guidelines (DERM, 2004). These guidelines provide the methods
used for this impact assessment in determining background noise levels (based on site-
specific noise monitoring data).
• AS 2436-1981: Guide to noise control on construction, maintenance and demolition sites.
These standards detail the typical equipment and the maximum sound power levels of
equipment at general construction sites. This information was used as the basis for
construction noise propagation modelling and the estimation of project noise levels at a given
sensitive receptor.
The standards that are relevant to the construction and operational phases of the project in
relation to vibration are:
• AS 2670.2-1990: Evaluation of human exposure to whole-body vibration – Part 2: Continuous
and shock induced vibration in buildings (1 to 80 HZ). This standard provides the magnitude of
vibration that approximates the human threshold of perception. To guarantee human comfort
and prevent complaints due to annoyance, vibration measurements should be below the levels
outlined in this standard.
• DIN 4150.3-1999: Structural vibration - Part 3: Effect of vibration on structures. This standard
outlines both intermittent and continuous acceptable vibration levels to ensure the structural
stability of various building types.
Any blasting activities that occur during construction will generate noise and ground vibration and,
potentially, flyrock. The relevant legislation and guidelines to address blasting are outlined below:
• Environmental Protection Act 1994. The act states that a person must not conduct blasting if:
– The airblast pressure is more than 115 dB Z peak for 4 out of any 5 consecutive blasts.
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– The airblast overpressure is more than 120 dB Z peak for any blast.
– For ground vibrations greater than 35 Hz, more than 25 mm/s ground vibration, peak
particle velocity.
– For ground vibrations of no more than 35 Hz, more than 10 mm/s ground vibration, peak
particle velocity.
• Guidelines for blasting noise and vibration (DERM, 2006). This Queensland guideline includes
the following provisions on noise and vibration criteria. Blasting activities must be undertaken
in a way that, if blasting noise does affect a sensitive receptor, then:
– The airblast overpressure must be no more than 115 dB (linear) peak for 9 out of any 10
consecutive blasts initiated, regardless of the interval between blasts.
– The airblast overpressure must not exceed 120 dB (linear) peak for any blast.
Blasting operations must also be carried out in a way that, if blasting vibration does affect a
sensitive receptor, then:
– The ground-borne vibration must not exceed a peak velocity of 5 mm/s for 9 out of any 10
consecutive blasts initiated, regardless of the interval between blasts.
– The ground-borne vibration must not exceed a peak particle velocity of 10 mm/s for any
blast event.
22.2 Assessment Method
This section describes the noise and vibration impact assessment study method. Noise related
legislation, regulations and guidelines have been used to establish project-specific noise and
vibration criteria that the project will meet during construction and operation. This approach allows
project impacts to be defined in direct terms, i.e., if project noise and vibration criteria are met
under the relevant legislation, impacts on sensitive receptors are acceptable.
The study established environmental values, identified sensitive receptors and assessment
locations, characterised existing (i.e., baseline) noise, vibration and meteorological conditions in
the study area, established project specific noise and vibration criteria, and predicted noise and
vibration levels that will occur due to project construction and operation.
An impact assessment on blasting has not been performed. Construction blasting requirements
will be determined after further site investigations have been completed and the civil design is
more advanced. General recommendations for blasting management and mitigation methods to
be implemented during construction blasting activities have been described.
22.2.1 Identification of Sensitive Receptors and Assessment and Measurement Locations
Sensitive receptors are land uses (generally residences) that have the potential to experience
impacts from the project. Receptors sensitive to noise and vibration impacts have been identified
due to their proximity to project infrastructure (e.g., temporary workers accommodation facilities
(TWAFs), launch sites, the LNG plant).
Six sensitive receptors were identified as ‘assessment locations’ (ALs), and they represent the
range of sensitive acoustic environments found within the Gladstone region (Figure 22.1).
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Compliance with the assessment criteria at these six ALs will ensure compliance at all potentially
affected sensitive receptors.
While ALs represent specific sensitive dwellings, measurement locations (MLs) represent where
land access was possible for measurement and monitoring activities. These locations were
selected for exhibiting similar existing acoustic conditions as the ALs. The relationship between
the noise measurement locations and sensitive receptor assessment locations is shown in
Table 22.1 and Figure 22.1.
22.2.2 Noise Impact Assessment Method
An explanation of noise level descriptors used for characterising (and assessing impacts on) the
noise environment is given below:
• LAeq – the A-weighted equivalent continuous sound level is defined as the steady sound level
that contains the same amount of acoustic energy as a given time varying sound over the
same measurement interval. It can be loosely thought of as the ‘average’ or ‘ambient’ level.
The A-weighting was designed to replicate the response of the human ear and is now
commonly used for the measurement of environmental and industrial noise.
• LA90 – the A-weighted sound level exceeded for 90% of a given measurement interval and is
representative of the average minimum sound level. It is often used to describe the
‘background’ level.
• Rating background level – the overall single figure background noise level representing each
assessment period (day, evening and night) over the whole monitoring period. The rating
background level is the baseline noise level used for the assessment of impacts.
Baseline Assessment
Noise monitoring was performed at five locations (see Figure 22.1) to characterise existing
background (LA90) and ambient (LAeq) noise levels from anthropogenic sources (e.g., vehicles,
industry, etc.) and natural sounds such as the wind, ocean waves and wildlife. This data was used
to calculate the rating background level. The five noise monitoring locations are representative of
existing acoustic conditions at the sensitive receptors. Periods of measurement at each location
are shown in Table 22.1.
Table 22.1 Baseline measurement period
Measurement Location Associated Sensitive Receptor
Assessment Location
Measurement Period
Start End
ML1 (Boatshed Point) AL1 (Tide Island), AL6 (Witt Island) 29 March 2010 14 April 2010
ML2 (Yarwun) AL2 (Targinnie) 29 March 2010 14 April 2010
ML3 (Fishermans Road) AL3 (Fishermans Road)1 1 April 2011 14 April 2011
ML4 (Lord Street) AL4 (Lord Street)2 1 April 2011 14 April 2011
ML5 (Flinders Street) AL5 (Flinders Street)3 1 April 2011 14 April 2011
Note: Background noise was measured at ML3 to ML5 at a later date as these sites were included in the study area later
in the project. 1 ML3 (Fishermans Road) and AL3 (Fishermans Road) are at the same location. 2 ML4 (Lord Street) and AL4 (Lord Street) are at the same location. 3 ML5 (Flinders Street) and AL5 (Flinders Street) are at the same location.
Impact Assessment
The characterisation of existing noise conditions enabled noise criteria for the construction and
operation of the project to be developed in accordance with the EPP (Noise) and Berglund et al.
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(1999) guidelines for community noise. Project construction and operation noise criteria are
provided in Table 22.2.
Table 22.2 Proposed project noise criteria for construction and operation
Activity Source Assessment
Location
Outdoor Noise Criterion (dB(A))
Day Evening Night
Construction Construction of LNG plant,
marine facilities, feed gas
pipeline and dredging
AL 1
All reasonable and practical
measures will be implemented
to reduce noise impacts.
45
AL 2
AL 3
AL 4
AL 5
AL 6
Operation
(continuous)
LNG plant AL 1
33 AL 6
AL 3
AL 2
28 AL 4
AL 5
Operation
(intermittent)
LNG carrier movements AL 1
50 50 45
AL 2
AL 3
AL 4
AL 5
AL 6
Construction noise limits are not specified in the Environmental Protection Act 1994 or the EPP
(Noise). However, amenity must be preserved during the night period at sensitive receptors, and
reference is made to the WHO guidelines (Berglund et al., 1999), which state that noise during
night-time periods should not exceed 45 dB(A) outside a dwelling.
Continuous operation noise criteria for the LNG plant have been developed with the aim of
avoiding cumulative impacts. Background noise levels at AL1, AL3 and AL6 were high, mostly
due to natural noise sources such as wind in trees and waves. A noise criterion of 33 dB(A) is
therefore proposed at these locations, which accounts for the cumulative noise from other
developments in the area. Background noise levels at AL2, AL4, and AL5 were lower. The
selected criterion of 28 dB(A) for these receptors allows for three developments to contribute
equally to achieve a cumulative noise level of 33 dB(A).
Intermittent operational noise criteria have been based on the EPP (Noise). Meeting these criteria
should preserve health and well-being, and avoid sleep disturbance at sensitive receptors.
Noise impacts were modelled using the internationally recognised Conservation of Clean Air and
Water in Europe (CONCAWE) noise propagation model (Manning, 1981). The CONCAWE model
takes into account the effects of terrain, locations of sensitive receptors and meteorological
conditions. Meteorological conditions used in the model have been based on the CONCAWE
system and are classified into six weather categories:
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• Category 1, 2 and 3 – wind blowing from the sensitive receptor towards the noise source
during daytime with little or no cloud cover.
• Category 4 – neutral weather conditions of no wind and an overcast day or night.
• Category 5 – no wind on a clear night (typical of a temperature inversion and greater noise
propagation than during Category 4 conditions).
• Category 6 – ‘worst-case’ conditions, when wind is blowing from the source toward the
sensitive receptor on a clear night (typical of a temperature inversion).
Wind blowing from the source to a receptor (i.e., Category 5 or 6) will generate higher noise levels
at the receptor than during Category 1 to 4 conditions at speeds up to 5 m/s. At higher speeds,
the noise of operating equipment is typically masked by the noise of wind in trees.
Twelve months of data from the Bureau of Meteorology for the Gladstone radar weather station
was analysed to determine the percentage of time each CONCAWE weather category occurred at
various sensitive receptors. The selection of appropriate assessment meteorological conditions is
based on this data.
Construction
Noise emissions from construction equipment are based on typical equipment likely to be used
during construction, taken from the Australian standard AS 2436-1981.
While not representative of typical construction activity, a conservative approach of continuous
and simultaneous equipment operation was adopted for the noise impact assessment. Noise
levels generated during construction of trains 1 and 2 will be similar to the combined noise levels
generated during construction of trains 3 and 4 while trains 1 and 2 are operating.
Operation
Noise levels generated during operation will vary depending on whether the LNG plant is powered
by onsite gas turbine generators or by the power taken from the Queensland electricity grid. Four
worst-case scenarios were assessed:
• Scenario 1: base case mechanical drive with two LNG trains operating.
• Scenario 2: all-electric power with two LNG trains operating.
• Scenario 3: base case mechanical drive with four LNG trains operating.
• Scenario 4: all-electric power with four LNG trains operating.
For each scenario, continuous and intermittent noise sources were assessed. Continuous noise
sources comprise plant and equipment that, under normal operating conditions, will occur
24 hours per day. Intermittent noise will occur over shorter periods (i.e., not continuous), typically
from sources such as LNG carriers and tug boats.
Continuous and intermittent noise sources such as the LNG plant and associated equipment
could generate low-frequency noise. A frequency analysis of all noise sources was conducted to
assess impacts of low-frequency noise on assessment locations. The draft guidelines for
assessing low-frequency noise (DERM, 2002b) have been used to assess this noise type.
22.2.3 Vibration Impact Assessment Method
Levels of vibration are a result of the acceleration of a particle and its frequency; measured
vibration levels for an object are measured along the x (horizontal), y (horizontal) and z (vertical)
planes. The human threshold of vibration is outlined in AS 2670.2-1990.
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Baseline Method
Manual vibration monitoring was performed at monitoring locations ML1 and ML2 on 14 April
2010 in accordance with AS 2670.2-1990.
The existing vibration levels at all measurement locations were well below the threshold of human
perception and were not detectable without vibration measuring equipment. Measured vibration
levels at ML1 and ML2 confirmed that the vibration levels were below the threshold of human
detection.
Based on the observations and vibration measurements, the existing vibration levels at all other
assessment locations were assumed to be below the threshold of human detection. This is a
conservative approach as the project will not use existing levels of vibration to justify higher
vibration from the project. Rather, the project will need to achieve the stringent vibration criteria
that are unrelated to existing levels.
Impact Assessment
Vibration criteria for project construction and operation were developed in accordance with
DIN 4150.3-1999, which provides criteria to assess structural damage impacts as a result of
vibration from the project.
Project-specific vibration criteria for construction and operation are provided in Table 22.3 and
include intermittent and continuous acceptable vibration levels for dwellings. These vibration
levels were used to assess impacts associated with project construction and operation.
Table 22.3 Vibration levels for dwellings
Vibration Level (mm/s)
Foundation of Dwelling Horizontal Plane at
Highest Floor of Dwelling 1 to 10 Hz 10 to 50 Hz Above 50 Hz
Intermittent (construction) 5 5 to 15 15 to 20 15
Continuous (operation) n/a n/a n/a 5
Source: DIN 4150.3-1999.
Impacts on human comfort were not assessed for project construction because these impacts are
intermittent in nature. Structural damage due to vibration was assessed during construction.
Impacts on both human comfort and structural damage were assessed during operation.
Predicted project construction and operation vibration levels used in the impact assessment were
based on previous measurements of activity during the construction and operation of analogous
projects.
The potential for ground vibration effects on underground pipelines and telecommunication lines
was also examined.
22.3 Existing Environment and Environmental Values
Existing noise and vibration conditions are controlled by different factors across the study area.
The natural sounds from waves and wind in the trees, as well as marine traffic noise, dominate
conditions within Port Curtis. In the urbanised and industrialised areas of Gladstone, local road
traffic and existing industry and commerce influence conditions. Further west of Gladstone in the
more rural areas, road traffic, lighter industry and natural sounds influence the acoustic
environment.
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22.3.1 Noise
The results of noise measurements are summarised in Table 22.4 and show the calculated rating
background levels for all noise monitoring locations.
Table 22.4 Calculated rating background levels
Noise Monitoring Location Associated Impact
Assessment Location
Rating Background Level (dB(A))
Day
Evening
Night
ML1 AL1, AL6 44 41 43
ML2 AL2 34 34 33
ML3 AL3 42 44 43
ML4 AL4 39 37 35
ML5 AL5 40 36 35
Note: Daytime – 7.00 a.m. to 6.00 p.m., Evening – 6.00 p.m. to 10.00 p.m., Night-time – 10.00 p.m. to 7.00 a.m.
22.3.2 Vibration
The existing vibration levels measured at ML1 and ML2 show that levels are below the thresholds
of human perception.
No other activities near the project area (such as major roads and quarrying activities) were found
to cause background levels of vibration.
22.4 Issues and Potential Impacts
This section describes the activities that will create noise and vibration during project construction
and operation, and resulting impacts, prior to implementing measures to attenuate noise.
22.4.1 Noise
Construction noise sources are discussed for the LNG plant site, laydown areas and construction
camps, marine facilities, feed gas pipeline and dredging activities.
The operation of the LNG plant will generate both continuous and intermittent noise.
Construction
During construction, noise will be generated at all work sites as described below.
• LNG plant site, lay down areas and construction camps:
– Site preparation and earthmoving: Heavy construction vehicles and equipment will include
bulldozers, scrapers, front-end loaders, backhoes, graders, rollers, dump trucks and water
carts.
– Civil works and plant fabrication: Concrete plant, installation of foundation structures and
paved areas within the LNG plant site will require equipment such as pile drivers, heavy
rollers, dump trucks, concrete trucks, generator sets and steel reinforcement fabrication
hand tools including grinders and welders.
– Construction and use of the haul road between the materials offloading facility (MOF) and
LNG plant: Equipment will include excavators, graders, rollers and dump trucks.
– Construction of the LNG plant: Activities such as receiving and transporting large plant
items (modules) from the MOF to the LNG plant site will typically require equipment such
as tugs and barges, offloading crawler cranes and heavy transport equipment. Onsite steel
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fabrication and pipe erection will typically require equipment such as tower cranes,
grinders, welders, generator sets and air compressors. Erection and assembly of plant
items will require equipment such as tower cranes, forklifts, generator sets and air
compressors.
Temporary elevations in the noise profile may occur from blasting, in addition to routine
construction noise. The blasting events will likely occur at irregular intervals.
• Marine facilities (MOF and personnel jetty, LNG jetty and mainland launch site):
– The work will require heavy construction equipment such as excavators, bulldozers, dump
trucks, graders, rollers and concrete trucks. Piling will be required for the MOF and
personnel jetty.
– Site preparation and earthmoving activities: These will be carried out by heavy construction
vehicles and equipment such as bulldozers, scrapers, front-end loaders, backhoes,
graders, rollers, dump trucks and water carts.
– Construction of the MOF, LNG jetty and mainland launch sites: Construction will typically
require equipment such as pile drivers and cranes.
– Dredging at all marine infrastructure sites to assist construction activities: Cutter suction
and backhoe dredgers will be used, supplemented by barges and support tender vessels.
• Feed gas pipeline:
– Open cut trenching: Noise will be produced from equipment such as front-end loaders,
welders, trenching machines, excavators, trucks, cranes and concrete mixers.
– Tunneling: Ancillary equipment such as slurry pumps will generate noise during
construction of the feed gas pipeline Port Curtis tunnel crossing.
Table 22.5 shows predicted noise levels at the impact assessment locations due to construction
activities.
Modelling of construction noise predicts that construction noise criteria will be exceeded at
sensitive receptor assessment locations AL1 and AL5 during night-time periods. Sensitive
receptor assessment location AL1 will be adversely affected during construction of the LNG plant,
MOF and personnel jetty (for both the Boatshed Point and South Hamilton Point options) and the
construction camps on Curtis Island. Noise criteria at sensitive receptor assessment location AL5
will only be exceeded during construction of TWAF 7.
Construction noise levels at all other sensitive receptor assessment locations (AL2, AL3, AL4 and
AL6) will comply with project noise criteria.
Operation
Operation noise sources are classified as either continuous (noise sources which operate
continuously over a 24-hour period) or intermittent (noise sources that will only occur for short-
term periods). The main continuous noise source during operation will be fixed equipment at the
LNG plant (i.e., LNG trains, gas turbines for the mechanical drive option, water facilities, loading
systems, substations, etc.).
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Table 22.5 Predicted noise levels during construction
Assessment
Location Construction Area
LNG Plant
Marine Facilities*
Feed Gas
Pipeline
Construction Camps
Boatshed Point
MOF and
Personnel Jetty
South Hamilton
Point MOF and
Personnel Jetty LNG Jetty Launch Site 1
Launch Site
4N
Curtis
Island TWAF 7 TWAF 8
AL1*
47 63 58 43 42 n/a 27 53 n/a 62
AL2 n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a
AL3 n/a n/a n/a n/a n/a 28 40 n/a n/a n/a
AL4 n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a
AL5 n/a n/a n/a n/a n/a n/a n/a n/a 61 n/a
AL6 n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a
Assessment
Location
Construction Area
Laydown Areas Dredge Sites
Curtis
Island Launch Site 1 Launch Site 4N
Curtis Island
and Launch
Site 1
Curtis Island
and Launch
Site 4N
Launch Site
1
Launch
Site 4N
Boatshed
Point
Hamilton
Point
South LNG Jetty
AL1* 44 33 23 44 44 28 18 53 50 33
AL2 17 10 20 18 22 5 12 12 8 14
AL3 27 18 19 27 27 13 12 22 21 25
AL4 31 27 15 32 31 18 11 29 25 24
AL5 26 30 15 31 26 23 11 23 19 21
AL6 42 31 20 42 42 24 16 45 39 30
Note:
n/a – sites that are too far away from construction noise sources to be impacted.
Bold italicised numbers indicate noise levels that exceed the proposed construction night-time noise criteria of 45 dB(A).
*The noise from construction of the marine facilities was assessed at the closest sensitive receptor (AL1) on the basis that the noise at all other locations would be lower.
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Modelling results for the four LNG plant operation scenarios are provided in Table 22.6. The bold
italicised numbers indicate noise levels that exceed the proposed project noise criteria.
Operational noise levels at sensitive receptor assessment locations AL1, AL4 and AL6 will exceed
project noise criteria under all scenarios; operational noise levels at sensitive receptor AL3 will
exceed project noise criteria under Scenario 3; and operational noise levels at sensitive receptor
AL5 will exceed project noise criteria under Scenarios 3 and 4, i.e., when four LNG trains are
operating, regardless of how the LNG plant is powered.
Table 22.6 Predicted noise levels from continuous operation activities
Assessment
Location
Noise
Criterion
dB(A)
Predicted Operational Noise Level dB(A)
All Mechanical Drive All Electrical Power
Two
LNG Trains
(Scenario 1)
Four
LNG Trains
(Scenario 3)
Two
LNG Trains
(Scenario 2)
Four
LNG Trains
(Scenario 4)
AL1 33 47 49 46 48
AL2 28 22 25 20 23
AL3 33 31 34 30 33
AL4 28 34 37 33 35
AL5 28 28 31 27 29
AL6 33 45 47 44 46
The noise from the LNG plant equipment is not dominated by low-frequency noise, but is made up
of a combination of high, mid and low frequency noises. As high and mid frequency noise
attenuates faster over large distances, a greater component of low-frequency noise will be
received at sensitive receptors. The DERM (2002b) Low Frequency Noise Draft Guideline
recommends acceptable levels of 20 dB(A) low-frequency noise within a dwelling. The predicted
low-frequency noise levels will be exceeded during operation.
Intermittent noise during operation, including LNG carriers and tug boats, will not exceed the
project noise criteria.
22.4.2 Vibration
Construction vibration sources are discussed for the LNG plant site, construction camps, marine
facilities and the feed gas pipeline. Vibration sources during operation are discussed for the LNG
plant, LNG jetty, and the feed gas pipeline.
Construction
Construction activities will cause vibrations at the following worksites.
• LNG plant site and construction camps:
– Civil works, foundations and plant fabrication: Equipment such as heavy rollers, dump
trucks, concrete trucks and generators will be involved. Piling will also be required to
construct the plant foundations.
– Construction of the LNG jetty: This work will typically require equipment such as pile
drivers.
– Intermittent blasting activities.
• Marine facilities (MOF and personnel jetty, LNG jetty and mainland launch site):
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– Construction: Heavy construction equipment will be used, such as excavators, bulldozers,
dump trucks, graders, rollers and concrete trucks. Sheet piling will be required for the MOF
and personnel jetty.
– Dredging: This work will involve cutter suction and backhoe dredgers and associated
support vessels.
• Feed gas pipeline:
– Open cut trenching. Equipment such as front-end loaders, excavators, trucks, cranes and
concrete mixers will be required.
– Tunneling. Ancillary equipment such as slurry pumps will be used during construction of the
feed gas pipeline Port Curtis tunnel crossing.
The distance between the LNG plant construction site and the closest sensitive receptor
assessment location at AL1 is 2.4 km, and vibration levels will be well below the threshold of
human detection. Therefore, the remaining assessment locations will similarly be unaffected as
they are even further away.
Vibration levels during construction will not impact on pipework or telecommunication lines within
the project vicinity because none currently exist.
Similarly, separation distances between all assessment locations and other construction sites and
activities (marine facilities, construction camps, the feed gas pipeline alignment and dredging) are
such that expected vibration levels will also be below the threshold of human detection.
Operation
Vibration at assessment locations during the operation of the project may be generated by the
operation of equipment at the LNG plant, LNG jetty and the feed gas pipeline. Vibration levels will
be well below the threshold of human detection due to the large separation distances of all
assessment locations from this infrastructure.
The feed gas pipeline will be located underground and the associated equipment is not expected
to produce a perceivable vibration on the land surface. Any underground pipework or
telecommunication lines located near the feed gas pipeline will not be structurally damaged as a
result of vibration. The vibration levels at assessment locations in the vicinity of the feed gas
pipeline are predicted to be well below the threshold of human detection.
22.5 Avoidance, Mitigation and Management Measures
This section describes the proposed avoidance, mitigation and management measures designed
to ensure compliance with noise and vibration criteria.
22.5.1 Noise
Construction mitigation measures will make use of attenuation devices on machinery, correct
handling and usage of noise generating equipment, and scheduling and coordination of the use of
noisy equipment during daytime periods.
Mitigation measures for operation focus on the acoustic treatments that will reduce noise impacts
when applied to the LNG plant and ancillary facilities.
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Construction
The following management and mitigation measures will be implemented to reduce construction
noise below the project criteria of 45 dB(A) during the night-time period:
• Where practical, locate noise making equipment to maximise the distance between noise
sources (e.g., diesel generators) and sensitive receptors. The use of structures or natural
topography to create barriers to noise may be used to lessen the noise impacts on sensitive
receptors. [C22.02]
• Regularly maintain all machinery and equipment and check for excessive noise generation.
[C22.04]
• Where noise from a construction activity would exceed the project night time noise criteria of
45 dB(A) at a sensitive receptor, schedule, where practical, construction activities to occur
between 7.00 a.m. and 10.00 p.m. [C22.05]
• Continually review the timing of construction activities to identify opportunities to reschedule
concurrent activities where excessive noise is expected. [C22.06]
Operation
Compliance with operational project noise criteria will require the application of acoustic
treatments. The potential treatment options to achieve compliance provided in Table 22.7 are
conceptual only, and are specified here to enable modelling of noise contours for the purposes of
the residual impact assessment. Arrow Energy will identify, during the detailed design of the LNG
plant, specific acoustic treatment to be applied to each noise source. [C22.01]
Table 22.7 Potential acoustic treatments
Noise Source Potential Acoustic Treatment
LNG Train Equipment (per LNG Train)
Process Compressors
Low-pressure compressor Sheet steel enclosure with acoustically treated ventilation.
Low-, medium- and high-pressure
compressor
Sheet steel enclosure with acoustically treated ventilation.
Gas turbine casing (100 MW) Sheet steel enclosure with acoustically treated ventilation.
Gas turbine exhaust stack (100 MW) Upgrade silencer.
Air Coolers
Fan bay (3 fans) Use of ultra-low noise fans, installation of variable fan
drives, incorporation of discharge air sound attenuators.
End Flash Gas Compression Unit
Compressor electric motor Sheet steel enclosure with acoustically treated ventilation.
Other Equipment at LNG Plant
Power Generator Drives
Gas turbine casing (30 MW) Sheet steel enclosure with acoustically treated ventilation.
Gas turbine exhaust stack (30 MW) Upgrade silencer.
Generator Sheet steel enclosure with acoustically treated ventilation.
Loading System
Boil off gas compressors Sheet steel enclosure with acoustically treated ventilation.
Environment Impact Statement
Arrow LNG Plant
Coffey Environments 7033_7_Ch22_v3
22-15
Table 22.7 Potential acoustic treatments (cont’d)
Noise Source Potential Acoustic Treatment
Other Equipment at LNG Plant (cont’d)
Water Facilities
High-pressure pump Sheet steel enclosure with acoustically treated ventilation.
Pump Sheet steel enclosure with acoustically treated ventilation.
22.5.2 Blasting Noise and Vibration
Blasting noise and vibration impacts associated with the project have not been assessed as
detailed information (e.g., location, size, timing and frequency) is not yet available. Any blasting
required during project construction will be confirmed and assessed as necessary at a later stage
of the project.
Arrow Energy will include appropriate methods to manage blasting activities in the construction
environmental management plan. If required, blasting activities will be carried out in accordance
with the guidelines for blasting noise and vibration (DERM, 2006). [C22.03]
22.6 Residual Impacts
Predicted operational noise levels at each assessment location, with the potential acoustic
treatments applied at the LNG plant, are provided in Table 22.8. Predicted noise contours with
potential acoustic treatment are shown in Figure 22.2. Arrow Energy will ensure that project
related noise generated during operation complies with the project noise criteria at all assessment
locations. [C22.07]
Table 22.8 Predicted noise levels from LNG plant operation with additional acoustic
treatment
Assessment
Location
Noise
Criterion
dB(A)
Predicted Operational Noise Level dB(A)
All Mechanical Drive All Electrical Power
Two
LNG Trains
Four
LNG Trains
Two
LNG Trains
Four
LNG Trains
AL1 33 33 33 33 33
AL2 28 11 12 11 12
AL3 33 19 20 20 21
AL4 28 22 22 22 22
AL5 28 16 16 16 17
AL6 33 31 32 31 31
The low-frequency noise levels (from operation of the LNG plant) inside the closest dwelling were
predicted assuming the potential acoustic treatments were in place and neutral meteorological
conditions. The predicted outcome of low-frequency noise levels at sensitive receptor AL1 for
both the mechanical drive (19 dB(A)) and all-electric option (18 dB(A)) are below the indoor noise
criterion of 20 dB(A) and are not expected to exceed project noise criteria. Sensitive receptor AL1
is the most affected assessment location and noise levels at all assessment locations will
therefore not exceed project noise criteria for low-frequency noise.
Environment Impact Statement
Arrow LNG Plant
Coffey Environments 7033_7_Ch22_v3
22-17
Project construction and operation activities will comply with project noise criteria assuming
implementation of the identified mitigation measures and acoustic treatments. As such, there are
no residual noise impacts. Vibration impacts are below the threshold for human detection and, as
such, there are no residual impacts.
22.7 Inspection and Monitoring
Background noise and vibration monitoring will be completed prior to construction commencing.
Noise and vibration monitoring will be undertaken during the construction and operation phases
on an ‘as required’ basis.
22.8 Commitments
The measures (commitments) that Arrow Energy will implement to manage impacts from noise
and vibration are set out in Table 22.9.
Table 22.9 Commitments: Noise and vibration
No. Commitment
C22.01 Identify during the detailed design of the LNG plant, specific acoustic treatment to be applied to
each noise source.
C22.02 Where practical, locate noise-making equipment to maximise the distance between noise sources
(e.g., diesel generators) and sensitive receptors. The use of structures or natural topography to
create barriers to noise may be used to lessen the noise impacts on sensitive receptors.
C22.03 Include appropriate methods to manage blasting activities in the construction environmental
management plan. If required, carry out blasting activities in accordance with the guidelines for
blasting noise and vibration.
C22.04 Regularly maintain all machinery and equipment and check for excessive noise generation.
C22.05 Where noise from a construction activity would exceed the project night time noise criteria of
45 dB(A) at a sensitive receptor, schedule, where practical, construction activities to occur
between 7.00 a.m. and 10.00 p.m.
C22.06 Continually review the timing of construction activities to identify opportunities to reschedule
concurrent activities where excessive noise is expected.
C22.07 Ensure that project related noise generated during operation complies with the project noise
criteria at all assessment locations.
Environment Impact Statement
Arrow LNG Plant
Coffey Environments 7033_7_Ch22_v3
22-18
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